Radon is the leading cause of lung cancer after smoking, killing 7,000-30,000 people annually. The combination of radon exposure and smoking produces a synergy that markedly raises the risk of mortality. For smokers exposure to low to moderate levels of radon, changing smoking behavior is the most efficient risk reduction strategy. The aim of this randomized trial is to test interventions for households where a smoker is present and there are detectable levels of radon. This competing renewal extends ongoing work, which demonstrated that utility, which demonstrated that utility company bill stuffers were an effective recruitment device and found that brief phone counseling produced short-term (3- month follow-up) changes across several outcome measures. This 4-year project will work with a new electric utility in a region with higher levels of radon. Smoking households that return bill stuffer coupons will be randomized to 1 of 4 conditions in a 2 X 2 factorial design: phone counseling versus no counseling by, video/CD-ROM versus no video/CD-ROM. Control households will receive standard EPA written materials on radon and smoking. All households receive feedback on their radon level. Telephone counseling is hypothesized to produce significant changes in smoking comparable to those found in our current study. The visual and potentially interactive displays possible in the video/CD-ROM are expected to produce changes comparable to the phone counseling. The combination condition is expected to be significantly better than either alone. Follow up assessments will be conducted by mail and phone. Sustained quitting of smoking at both 3 and 12 months and changes in household smoking rules are primarily outcome measures. Adjunctively, we will examine participants' mental models of radon smoking risk using revised measures and conducting subanalyses on high radon households. The interventions are potentially disseminable at low cost and, collaboratively with utility companies, could motivate large numbers of households to test for radon and take appropriate risk reduction strategies.